"in" everywhere

[Jonathan M Davis]

On Thursday, October 07, 2010 16:39:15 Tomek Sowiński wrote:
> Simen kjaeraas napisał:
> > Tomek Sowiński <just at ask.me> wrote:
> >> Even if the attribute properties could see the arguments, how to deal
> >> with things like
> >> lhs.length + rhs.length? It has to be inspectable at compile-time. One
> >> idea is to store the
> >> expression's abstract syntax tree (we want AST macros in D3 anyway)...
> >> But I got a feeling
> >> we're heading for an overkill :)
> > 
> > Just as soon as we solve the halting problem, eh?
> 
> What's the halting problem?

http://en.wikipedia.org/wiki/Halting_problem

It's a classic problem in computer science. Essentially what it comes down to is 
that you can't determine when - or even if - a program will halt until it 
actually has. It's why stuff like file transfer dialogs can never be totally 
accurate. And best, you can estimate how long a file transfer will take based on 
the current progress, but you can't _know_ when it will complete. It's even 
worse for algorithms where you can't even estimate how much work there is left. 
And of course, you don't even necessarily know that the program _will_ halt. It 
could be an infinite loop for all you know.

- Jonathan M Davis